Oxyrhopus formosus Wied, 1820

De Alencar, Arília Aiarsa Laura R. V. & Martins, Marcio, 2013, Natural History Of Pseudoboine Snakes, Papéis Avulsos de Zoologia 53 (19), pp. 261-283 : 267

Oxyrhopus formosus Wied, 1820

Distribution: Oxyrhopus formosus is distributed throughout the Amazon basin in Brazil, Bolivia, Colombia, Ecuador, the Guianas, Peru, and Venezuela, as well as in eastern Brazil (e.g., Hoge et al., 1972; Cunha & Nascimento, 1978, 1983, 1993; Duellman, 1978; Gasc & Rodrigues, 1980; Silva, 1993; Martins & Oliveira, 1998; Starace, 1998; Mattei & Barrio, 1999; Santos-Costa, 2003; Argôlo, 2004; Frota et al., 2005; Prudente et al., 2010; Silva et al., 2010; Bernarde et al., 2011; H. Zaher, unpublished data).

Habitat and time of activity: This moderate-sized pseudoboine (maximum SVL = 897 mm, female; Silva, 1993) inhabits forests and appears to be restricted to pristine habitats ( Gasc & Rodrigues, 1980; Martins & Oliveira, 1998; Santos-Costa, 2003; Argôlo, 2004; A. Dourado, unpublished data; S. Morato, unpublished data). It seems to be a semi-arboreal species (terrestrial data: N = 9; Duellman, 1978; Martins & Oliveira, 1998; Santos-Costa, 2003; A. Dourado, unpublished data; S. Morato, unpublished data; arboreal data: N = 6; Gasc & Rodrigues, 1980; Martins & Oliveira, 1998; Duellman, 2005; P. Bernarde, unpublished data), active mainly during the night (N = 12; Duellman, 1978, 2005; Gasc & Rodrigues, 1980; Martins & Oliveira, 1998; P. Bernarde, unpublished data), but there are two observations of diurnal activity ( Santos-Costa, 2003; A. Dourado, unpublished data).

Feeding: Oxyrhopus formosus feeds on lizards (N = 7; Duellman, 1978; Santos-Costa, 2003; this study).

Reproduction: Clutch size varied from four to 17 eggs (mean = 11.3 eggs, N = 3; Duellman, 1978; Starace, 1998).

Defense: According to Martins & Oliveira (1998), when handled O. formosus can thrash the body, and one adult bit after being handled for a long period. These authors also suggest that the color pattern of young and subadults may represent a case of abstract coral snake mimicry.

Remarks: We are aware that what we are calling Oxyrhopus formosus is a complex of distinct species with similar morphology and coloration, including the forms recently treated as O. occipitalis in the literature ( Lynch, 2009; MacCulloch et al., 2009). Athough there has been recent local attempts to clarify the taxonomic problems related to this complex ( Lynch, 2009; MacCulloch et al., 2009), the situation is still confusing and we hereby prefer to treat all the populations traditionally considered as O. formosus under this name, pending a revision of the complex that is underway (H. Zaher, pers. com.).